FX send / return

[Robert Broadley]

The Addition of Effects Send and Return channels would be really useful, to allow both software and hardware effect packages to be connected to mixxx.

There should be a way of selecting each deck, mic, L +R side of crossfader and the master to send to these effects channels.

This could later be integrated into the larger effects set currently in development.

[Owen Williams (ywwg)]

It would also be cool if those effects sends could be sent to actual audio devices for integration with JACK or actual effects boxes. Implementation would just be putting a shim between the decks and the mixer parts of the engine.

[Robert Broadley (rob2192)]

I think the easiest way to implement it at the moment would to link it with with the current effects and have a button to turn send/return on and of, then use current FX buttons to add effects to Deck 1 or 2.
The channels to input / output should be configurable in preferences, in the same way as all other ins and outs.

This can latter be built in to a complete effects package where send/return is an effect that can be selected, just like pro mixers and some other software.

[Be (be.ing)]

As discussed in https://github.com/mixxxdj/mixxx/pull/1254#issuecomment-346853954 , external software effects would be supported much better by implementing support for plugin formats designed for this purpose such as LV2 (Bug #1530238) and VST (Bug #1740335). We cannot use Mixxx's controller mapping system to interface with separate programs in a reliable and intuitive way, but we can do that with effect plugins.

As for send/return loops with hardware effects, that is not technically possible because our effect units have switchable inputs and a hardware send/return loop introduces more latency. The extra latency could only be compensated for to keep all channels aligned if the signal path was fixed. Switching the latency of a signal path during playback would create brief gaps of silence and the signal path with added latency would be misaligned in time with the other channels.

[Daniel Schürmann (daschuer)]

Can't we do this already? We can pass the r/l bus to an external app and return it to Mixxx via Aux? What is missing to use this in a priority DAW setup?

[Daniel Schürmann (daschuer)]

priority -> professional

[Be (be.ing)]

Professional DAW setup? Mixxx is not a DAW, nor it should it be. If we aim to make Mixxx a DAW, we will overcomplicate its use as a live performance tool.

[Swiftb0y (swiftb0y)]

Mixxx now uses GitHub for bug tracking. This bug has been migrated to:
https://github.com/mixxxdj/mixxx/issues/6835